The extent of the devastation in Burma is only just coming to light several days after Cyclone Nargis hit the country. It's becoming clear that the scale of the disaster is as widespread and catastrophic as the recent south Asian tsunami.

Then, the world mobilised an unprecedented aid effort, led by presidents and prime ministers and donations from millions of people, following wall-to-wall coverage of the disaster. Thanks to the immense efforts of aid agencies, world leaders, the media and the public, support quickly reached the vast areas left devastated with no water, food or shelter. Had this not happened the death toll would have undoubtedly been significantly higher. We would not have been forgiven.

Unforgivably, the same cannot be said in the wake of Cyclone Nargis. As Glenys Kinnock wrote in the Guardian yesterday, the military regime is in effect blocking aid and assistance. Without access into the country, supplies of clean water, transport and shelter cannot be restored. And without being able to go to the affected areas, aid agencies and international organisations are unable to assess the damage and provide appropriate support.

As each day passes, disease spreads, water runs dry and people starve.

The challenge for the international community in the aftermath of this natural disaster is not so much one of mobilisation of resources and aid, but of gaining entry to a country which has been closed to the outside world for too long.

This challenge requires a major international political movement equivalent to the enormous charitable movement that emerged after the tsunami. Then, the pressure of populations around the world forced governments and institutions to act. We must now do the same.

As Glenys and other campaigners advocate, strong pressure should be applied by the EU, the UN and others to neighbouring countries, like Thailand, India and China, who have a better relationship with the military leadership in Burma to ensure that restrictions on visas and entry are lifted immediately.

Time is running out. The high death toll continues to rise. Burma is on the brink of a humanitarian catastrophe.

We cannot stand back in the face of a regime denying humanitarian aid to tens of thousands of desperate people. We would not be forgiven.